Leap 42.1 ships with a 64K page size kernel, whereas Leap 42.2 inherited the 4K
page size from SLES12 SP2.

It has been reported that since btrfs (the default filesystem) uses the native
page size as the block size or so, this leads to ...

a) the offline upgrade (.iso) not working (installation kernel can't mount the
filesystem),

b) the online upgrade (zypper dup) working but resulting in a non-bootable
system when using the 42.2 kernel.

Our intent is to fix this in multiple steps:

1) For Beta 2 switch kernel back to 64K page size.

This will immediately unbreak the upgrade path for any SoftIron customers and
other 42.1 users, but will break the Beta 1 upgrade path.
It will also affect whether any semi-official, not yet prepared/built 42.2 JeOS
images will be able to boot on low RAM due to large nr. of files in Kiwi
initrd.

2) Investigate a btrfs KMP that adds support for non-native page sizes.

That may allow to switch the page size to 4K for real, if we want.